Re: [PATCH 4/5] drm/amdgpu: Fix null pointer dereference to bo

[Christian König <christian.koenig@xxxxxxx>]

Am 13.05.24 um 10:56 schrieb Ma Jun:
> Check bo before using it
>
> Signed-off-by: Ma Jun <Jun.Ma2@xxxxxxx>

Reviewed-by: Christian König <christian.koenig@xxxxxxx>

> ---
>   drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c | 16 +++++++++++-----
>   1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c
> index 2b7b67916c1d..8269fd6828bf 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c
> @@ -497,9 +497,8 @@ static void gmc_v12_0_get_vm_pte(struct amdgpu_device *adev,
>   				 uint64_t *flags)
>   {
>   	struct amdgpu_bo *bo = mapping->bo_va->base.bo;
> -	struct amdgpu_device *bo_adev = amdgpu_ttm_adev(bo->tbo.bdev);
> -	bool coherent = bo->flags & AMDGPU_GEM_CREATE_COHERENT;
> -	bool is_system = bo->tbo.resource->mem_type == TTM_PL_SYSTEM;
> +	struct amdgpu_device *bo_adev;
> +	bool coherent, is_system;
>   
>   
>   	*flags &= ~AMDGPU_PTE_EXECUTABLE;
> @@ -515,13 +514,20 @@ static void gmc_v12_0_get_vm_pte(struct amdgpu_device *adev,
>   		*flags &= ~AMDGPU_PTE_VALID;
>   	}
>   
> -	if (bo && bo->flags & (AMDGPU_GEM_CREATE_COHERENT |
> +	if (!bo)
> +		return;
> +
> +	if (bo->flags & (AMDGPU_GEM_CREATE_COHERENT |
>   			       AMDGPU_GEM_CREATE_UNCACHED))
>   		*flags = (*flags & ~AMDGPU_PTE_MTYPE_GFX12_MASK) |
>   			 AMDGPU_PTE_MTYPE_GFX12(MTYPE_UC);
>   
> +	bo_adev = amdgpu_ttm_adev(bo->tbo.bdev);
> +	coherent = bo->flags & AMDGPU_GEM_CREATE_COHERENT;
> +	is_system = bo->tbo.resource->mem_type == TTM_PL_SYSTEM;
> +
>   	/* WA for HW bug */
> -	if ((bo && is_system) || ((bo_adev != adev) && coherent))
> +	if (is_system || ((bo_adev != adev) && coherent))
>   		*flags |= AMDGPU_PTE_MTYPE_GFX12(MTYPE_NC);
>   
>   }